Welcome, RebelAngel! Your pond is very nice. I bet that little red wagon was grunting if it handled some of those big rocks.
The Japanese Maples grow slow, but there are varieties that only get to be 3' tall when fully grown. Your significant other will know which ones are best for specimen trees by the pond. I bought one, haven't planted it yet, still waiting for the rains to stop so I can DIG! Thanks for the pics! Enjoy your pond, you earned it.